Alan bike box? My 58 size road frames fit in with no problems. I take off seatpost and stem with the bar.

If you're in Europe, the PBK box looks good for the price. The Bike Box Alan is a safe bet but a chunk more expensive IIRC.
I haven't tried it but a friend just got one and has tried his size 54 Felt B16 in it. Seems happy enough.

After trying 5 different bike boxes, I can say that with no doubt the Premier bike box is the best one I've used. A superior case and superior service as well. Highly recommended. Its really nice to get off the plane and find #1 my bike intact and #2 not a hassle to put back together. All other cases I've had at least trouble with one of the two.